Breaking the rules with better results heat treating 5160

M

mtemen

Member
I am making knives with 5160 and haven't been consistently successful at getting 60+ HRC after the quench. I have triple Normalized 1650,1550,1450 10 minutes each, then 1475 for 15 minutes and quench in 130 deg Canola oil. AVG HRC pre temper has been 58. Then I tried something different and I skipped the Normalizing and went directly to HT at 1600 for 15 minutes (Put the blade in a hot oven at 1600 for 15 mins) and quench in 130 deg Canola oil and got HRC 62.

I am new to this so what have I given up to get this hardness? What is going on with my grain growth?

Thx M
 
I would not get to hung up on numbers. Make some test knives using the 2 different heat treats and abuse them to destruction. Every steel performs differently at a given hardness. The only way to tell what gives you the best performance is through testing.
 
1475°F is too low for 5160 even without the normalizing, especially in the lower ranges, will pull carbon further out of solution and give much more decarb. The target temperature for 5160 is 1525°F, but the most you should expect with its carbon level is around 62 HRC. I would double check your grain size at 1600°F, it is quite high and larger grains will increase hardenability.
 
Ty Adams said:
I would not get to hung up on numbers. Make some test knives using the 2 different heat treats and abuse them to destruction. Every steel performs differently at a given hardness. The only way to tell what gives you the best performance is through testing.
Click to expand...

This is my solution too BUT Kevin is the steel guru and KNOWS his business so either if these will get you results, though admittantly, Kevin’s will be faster I just enjoy testing my knives so testing results are MY indicator of success.
 
Thanks everyone for weighing in. I guess i need to snap a knife and look at the grain size. Not sure I really know what I'm looking at but I'll post a picture and maybe someone can comment. Standby...
 
Maybe this will help with knowing what you are looking at, or looking for! 5160 is not my steel and I would be lying if I said I knew how to advice you on it!! But there are some on here that actually know more about this than 90% or the makers!!

I am going to give you the same advice I got when I first started learning about making knives and that there was much more to this than just grinding out a knife shaped object. The man I call my adopted mentor, (I adopted him, not the other way around) :D he told to listen and learn. There were a lot of folks who give advice and some of them knew what they were talking about!

He told me that if I ever saw anything from either of these two knife makers to sit up, and pay attention, to what they were sharing because neither of them will steer you wrong! Read and re-read anything they will share with you about knife making and HT!

One of those names was Karl Anderson and the other was Kevin Cashen.

Not only does Kevin give you the advice, he actually knows what he is talking about and he usually can explain it in a way that even I can understand. Now granted I may have to read it a couple of times but I usually get it!! :eek::cool:
This is web site, http://www.cashenblades.com/info.html

And if you goggle HT of 5160 by Kevin Cashen this is where you will end up, http://www.cashenblades.com/steel/5160.html

But you can get to the same place by clicking on the various links on his site!!
 
When you break a blade to look at the grain what you want to see is something that looks like gray satin. If you see something like fine sand then you are getting the blade too hot somewhere along the line. If it looks like table salt then you really over cooked it. Properly done, heat cycling will correct grain size by forcing it to reform going through the cycles without giving the grain the heat and time needed to grow. Then make sure that you don't overheat again austenizing prior to quenching.

Doug
 
mtemen said:
Thanks everyone for weighing in. I guess i need to snap a knife and look at the grain size. Not sure I really know what I'm looking at but I'll post a picture and maybe someone can comment. Standby...
Click to expand...
rather than break it, put a handle on it, sharpen it, then use the heck out of it. try a better HT on next knife
 
I forgot I had these pictures! It shows the various grains from HT!

The first picture shows and inconsistent grain!Inconsistent grain.png

The second one shows a large grain!
Large grain.png


And this last one is a poor to excellent grain!Poor to excellent grain.png
Hope that will show you more about what you may be looking at on the grain of the steel after a completely successful HT!
 
Here's what I show after my HT for a 5160 blade. Here are the details;
8 1/2" blade, 7/32 thickness. No Normalizing. Dipped in Turco. Place in 445 degree oven and brought to 1600 degrees within 20 minutes, then soaked for an additional 15 minutes. Quenched in Canola Oil at room temp. Tempered twice in 400 degree oven for 1 hr each.(cooled to room temp between tempering) Ground off all the scale and Measured HRC 55.

Any thoughts?

M
 

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